60 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 84 



downward and forward about as in related species to a point well below 

 and before the base of the fin, the opening about half width of the 

 pectoral base. Orig:in of dorsal fin above posterior third of the ap- 

 pressed pectoral, the fin of medium height and joined to the caudal 

 by membrane. Anal similar to dorsal, but much shorter, joined to 

 caudal by membrane. Scales very small, covering body and head 

 except snout and lower jaw, the rows of scales at the base of the dorsal 

 and anal fins diverging outward and backward on a narrow flat plane 

 the full length of the fin base. Scales with 33 radiating striae. 

 Myomeres conspicuous, 19 body and 22 caudal =41 muscular impres- 

 sions. Vertebrae, 20 body and 22 caudal =42. Color brownish 

 above, pale below, the head and sides with small dark-brown spots, 

 these forming faint dark bars under the lower jaw, the dorsal fin with 

 faint dark spots, an indication of faint dark bars radiating from 

 the eye. 



Two specunens, 51 and 65.5 mm in standard length, the smaller from 

 Panama Reef, collected by Meek and Hildebrand ; the larger example 

 from a tide pool at Panama, taken by Dr. Charles II. Gilbert. 

 U.S.N. M. nos. 50396 and 82677. 



This species is close to M. jloridanus (Longley) but differs in fin 

 formula, gill opening, and proportional measurements. From 

 M. aethiopicus it is distinguished by the smaller gill opening and more 

 anterior insertion of the dorsal fin. 



MICRODESMUS FLORIDANUS (Longley) 



Figure 9, a; Figure 10, b; Plate 2, Figure 2 



Cerdale floridana Longley, Carnegie Inst. Washington Year Book for 1933-1934, 

 no. 33, p. 259, 1934 (Tortugas). 



Body^ comparatively'' short, compressed, the greatest depth midway 

 between origin of dorsal and vent; caudal portion without fin, a little 

 shorter than rest of body, the vent situated midway between base of 

 caudal fin and anterior margin of eye. Head 6 to 7.2 in standard 

 length; depth S.5 to 9.5; predorsal 4.3 to 4.9; preventral 5.9 to 6.8; 

 base of ventrals to vent 2.6 to 2.9; preanal 1.9; caudal without fin 

 2.1 to 2.2. Snout short 5.5 to 7.7 in length of head, measured to gill 

 opening; interorbital 4.7 to 6.4; eye 4.1 to 6.0. The eye is compara- 

 tively larger in the smaller examples. Dorsal 45 to 47; anal 30 to 33; 

 pectoral 12; ventral 1-3. Eye rather large, about equal to length of 

 snout, lateral in position, iris silvery. Mouth small, little oblique, 

 the maxillary not nearly reaching anterior edge of orbit; lower jaw 

 projecting, with a small fleshy conical tip forming the anterior profile 

 of the head. Lips small, restricted laterally, the free folds not passing 

 around the mouth anteriorly. Snout and lower jaw with longitudinal 

 ridges and muscular folds, though not so well developed as in related 



